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Proposed Rule

Airworthiness Directives; McDonnell Douglas Model DC-9 Airplanes and Model MD-88 Airplanes

Document Details

Information about this document as published in the Federal Register.

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Start Preamble

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking; reopening of comment period.

SUMMARY:

This document revises an earlier proposed airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9 airplanes and Model MD-88 airplanes, that would have required replacement of certain power relays, and subsequent repetitive overhauls of the replaced power relays. That proposal was prompted by reports indicating that the alternating current (AC) cross-tie relay shorted out internally, which caused severe smoke and burn damage to the relay, aircraft wiring, and adjacent panels. This new action revises the proposed rule by revising the requirements and referencing new service information. The actions specified by this new proposed AD are intended to prevent internal arcing of the left and right generator power relays, auxiliary power relays, and external power relays, and consequent smoke and/or fire in the cockpit and cabin.

DATES:

Comments must be received by July 26, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-90-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 99-NM-90-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024). This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Elvin Wheeler, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5344; fax (562) 627-5210.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be Start Printed Page 44120considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

  • Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
  • For each issue, state what specific change to the proposed AD is being requested.
  • Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 99-NM-90-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-90-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add an airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9 airplanes and Model MD-88 airplanes, was published as a supplemental notice of proposed rulemaking (NPRM) in the Federal Register on June 14, 2001 (66 FR 32276). That original supplemental NPRM (hereafter referred to as “the first supplemental NPRM”) would have required replacement of certain power relays, and subsequent repetitive overhauls of the replaced power relays. The first supplemental NPRM was prompted by reports indicating that the alternating current (AC) cross-tie relay shorted out internally, which caused severe smoke and burn damage to the relay, aircraft wiring, and adjacent panels. That condition, if not corrected, may result in in-flight electrical fires.

Actions Since Issuance of Previous Proposal

1. Issuance of AD 2001-20-15

Since the issuance of the first supplemental NPRM, the FAA has issued AD 2001-20-15, amendment 39-12463 (66 FR 51857, October 11, 2001), which is applicable to certain McDonnell Douglas Model DC-9 airplanes and MD-88 airplanes. That AD requires an inspection to determine if a certain AC cross-tie relay is installed; replacement of a certain AC cross-tie relay with a new AC cross-tie relay; and repetitive cleaning, inspection, repair, and testing of a certain AC cross-tie relay. As discussed in the preamble of that AD, we determined that AC cross-tie relays having part number (P/N) 914F567-3 or -4 pose a more serious safety condition than previously determined in the first supplemental NPRM. As a result, actions required for the AC cross-tie relays, P/Ns 914F567-3 and -4, that were specified in the first supplemental NPRM have been specified in AD 2001-20-15. Therefore, we have revised this second supplemental NPRM by removing the actions that would have been required for the AC cross-tie relays, P/Ns 914F567-3 and -4.

2. Issuance of AD 2002-08-09

The FAA also has issued AD 2002-08-09, amendment 39-12717 (67 FR 19637, April 23, 2002), which is applicable to one McDonnell Douglas Model DC-9-31 airplane, fuselage number 0705. The requirements of that AD for the DC-9-31 airplane are identical to those described above for the airplanes affected by AD 2001-20-15.

3. Explanation of New Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin DC9-24A191, Revision 01, dated January 9, 2002. The service bulletin describes procedures for a one-time inspection of the generator power relays, auxiliary power relays, and external power relays to determine if a certain Sundstrand (Westinghouse) P/N is installed; and corrective actions, if necessary. The corrective actions include modifying and reidentifying the power relay assemblies; installing certain power relay assemblies within service interval limits; replacing the existing power relay assemblies with power relay assemblies that are within service interval limits; and cleaning, inspecting, repairing, and testing of relay assemblies; as applicable. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

4. Differences Between the Second Supplemental NPRM and the Referenced Service Bulletin

Operators should note that, although the procedures described in Boeing Alert Service Bulletin DC9-24A191, Revision 01, dated January 8, 2002, specify maintenance (i.e., clean, inspect, repair, and test) of power relays, Sundstrand (Westinghouse) P/N 9008D09 series, when they are beyond service interval limits, the second supplemental NPRM does not require those procedures. For further explanation, see heading “Request to Delete Certain Requirements” in the preamble of the second supplemental NPRM.

Operators should also note that the second supplemental NPRM would not require installation of certain power relays or replacement of the existing power relays with power relays that are “within service interval limits” (i.e., 7,000 flight hours) as described in the service bulletin. The FAA has determined that any generator power relay, auxiliary power relay, or external power relay having Sundstrand (Westinghouse) P/N 914F567-4 that is removed from the airplane must go through maintenance and be made serviceable before the power relay can be reinstalled on an airplane. Therefore, the second supplemental NPRM would require cleaning, inspecting, repairing, and testing of power relays having Sundstrand (Westinghouse) P/N 914F567-4, or replacing those power relays with serviceable power relays having Sundstrand (Westinghouse) P/N 9008D09 series or 914F567-4. The second supplemental NPRM also would require subsequent repetitive cleaning, inspecting, repairing, and testing of power relays having Sundstrand (Westinghouse) P/N 914F567-4.

Comments Received to First Supplemental NPRM

Due consideration has been given to the comments received in response to the first supplemental NPRM.

Request To Delete Certain Requirements

Several commenters request that the repetitive overhauls for power relay, Sundstrand (Westinghouse) P/N 9008D09 series, specified in paragraph (c) of the first supplemental NPRM, be deleted. The commenters state that there Start Printed Page 44121are no failure modes for that relay that result in the identified unsafe condition specified in the first supplemental NPRM. One commenter states that the design of the main contact arc box for this relay is entirely different than that of power relays, Sundstrand (Westinghouse) P/Ns 914F567-3 and -4, and is not susceptible to the same type of failure in the AC cross-tie position.

The FAA agrees that power relays having Sundstrand (Westinghouse) P/N 9008D09 series are not subject to the identified unsafe condition of the second supplemental NPRM. Therefore, we have deleted the repetitive overhaul requirements for P/N 9008D09 from the second supplemental NPRM.

Requests for Clarification of Applicability

Several commenters request clarification of the applicability to ensure that operators are cognizant of the repetitive overhaul requirements in paragraphs (b), (c), and (d) of the first supplemental NPRM. The commenters note that the applicability of the first supplemental NPRM affects “Model DC-9 series airplanes and Model MD-88 airplanes, equipped with Westinghouse alternating current (AC) power relays, part number (P/N) 914F567-3.” However, the proposed repetitive overhauls specified in paragraphs (b), (c), and (d) of the first supplemental NPRM are for airplanes equipped with power relays, Sundstrand (Westinghouse) P/Ns 914F567-4 and 9008D09 series, and for airplanes on which the flight hours since modification or installation of the AC power relay cannot be determined.

The FAA agrees that the applicability needs to be clarified. Because the proposed actions for AC cross-tie relays having Sundstrand (Westinghouse) P/N 914F567-3, and power relays having Sundstrand (Westinghouse) P/N 9008D09 series, have been deleted from the second supplemental NPRM, only the left and right generator power relays, auxiliary power relays, and external power relays, Sundstrand (Westinghouse) P/Ns 914F567-3 and -4, are subject to the requirements of the second supplemental NPRM. We have determined that a one-time inspection of the left and right generator power relays, auxiliary power relays, and external power relays to determine if Sundstrand (Westinghouse) P/N 914F567-3 or -4 is installed, is necessary (see heading “3. Explanation of New Service Information”). Therefore, we have deleted the phrase “equipped with Westinghouse alternating current (AC) power relays, part number (P/N) 914F567-3” from the applicability of the second supplemental NPRM.

Further, we have revised model designations in the applicability of the second supplemental NPRM to reflect the model designations as published in the most recent type certificate data sheet for the affected airplanes. These model designations are also identified in the effectivity of the referenced service bulletin. Because of these changes, we have also updated the number of affected airplanes in the Cost Impact Section of the second supplemental NPRM.

Requests To Revise Certain Compliance Times

Several commenters request that the 30-day compliance time for overhauling the power relays on the airplanes on which the flight hours since modification or installation of the AC power relay cannot be determined, as specified in paragraph (d) of the first supplemental NPRM, be extended.

Several commenters suggest a compliance time of 12 months. Two of these commenters request the extension for AC power relays, Sundstrand (Westinghouse) P/Ns 914F567-3 and -4, and power relays, Sundstrand (Westinghouse) P/N 9008D09 series, of an undetermined service life for all positions. One of the commenters requests the extension for AC power relays, Sundstrand (Westinghouse) P/Ns 914F567-3 and -4, of an undetermined service life in the cross-tie position only. The commenters note that paragraph (a) of the first supplemental NPRM allows AC power relays, Sundstrand (Westinghouse) P/N 914F567-3, for all positions, to remain in service for 12 months before replacement. Since the primary safety concern of the first supplemental NPRM is related to power relays, Sundstrand (Westinghouse) P/N 914F567-3, the commenters state that the compliance time for the power relays, Sundstrand (Westinghouse) P/N 914F567-4, of an undetermined service life should be the same as that of power relays, Sundstrand (Westinghouse) P/N 914F567-3 (i.e., 12 months). One of these commenters and another commenter state that 30 days is not enough time to obtain parts. One commenter also states that the lead-time for obtaining parts is 245 days.

One commenter suggests a compliance time of two years or at the next heavy maintenance check, whichever occurs first, and another commenter suggests 90 or 120 days. The two commenters support the 30-day compliance time for power relays at the cross-tie position only, but request the extensions for all relays at the generator power, auxiliary power, and external power positions. A third commenter also supports the 30-day compliance time for power relays at the cross-tie position only, but does not request an extension for the power relays in the other positions. One commenter states that relays at the generator power, auxiliary power, and external power positions are not as susceptible to the identified unsafe condition and should be allowed to remain on the airplane until the next heavy maintenance check. The commenters also state that such an extension for those power relays will not compromise safety and will allow the proposed overhaul to be accomplished during normal maintenance schedules.

One commenter requests that the 30-day grace period specified in paragraphs (b)(2) and (c)(2) of the first supplemental NPRM be extended for relays at the generator power, auxiliary power, and external power positions only. The commenter provides similar justification as identified above for extending the compliance time of paragraph (d) of the first supplemental NPRM.

The FAA partially agrees. As discussed previously, certain actions required for the AC cross-tie relay having Sundstrand (Westinghouse) P/Ns 914F567-3 and -4, and Sundstrand (Westinghouse) power relays having P/N 9008D09 series, that were specified in the first supplemental NPRM have been deleted from the second supplemental NPRM. Therefore, the commenters' requested changes for those power relays in the second supplemental NPRM are unnecessary.

However, we agree that, for airplanes on which the flight hours since installation of any generator power relay, auxiliary power relay, or external power relay, Sundstrand (Westinghouse) P/N 914F567-4, cannot be determined, the compliance time specified in paragraph (d) of the first supplemental NPRM (redesignated as paragraph (c)(2) in the second supplemental NPRM) should be extended from 30 days to 24 months. We also agree that the 30-day grace period specified in paragraph (b)(2) of the first supplemental NPRM (redesignated as paragraph (c)(1) in the second supplemental NPRM) for relays at the generator power, auxiliary power, and external power positions should be extended to 24 months.

We have reviewed the service bulletin (discussed previously) submitted by the manufacturer as to recommended maintenance (i.e., cleaning, inspecting, repairing, and testing) period (i.e., 24 Start Printed Page 44122months). We have determined that extending the proposed compliance time of 30 days specified in paragraph (d) of the first supplemental NPRM (redesignated as paragraph (c)(2) in the second supplemental NPRM) and the proposed grace period of 30 days specified in paragraph (b)(2) of the first supplemental NPRM (now specified in paragraph (c)(1) in the second supplemental NPRM) to 24 months will provide an acceptable level of safety. Therefore, we have revised the compliance time for maintenance of generator power relays, auxiliary power relays, and external power relays, Sundstrand (Westinghouse) P/N 914F567-4, specified in the second supplemental NPRM accordingly.

Request To Reconsider Use of Term “Overhaul”

Several commenters request that the FAA reconsider the use of the term “overhaul” in the first supplemental NPRM. One commenter suggests using the phrase “between removals” instead to avoid misinterpretation. Another commenter suggests the use of the term “maintenance.” One commenter notes that power relays, Sundstrand (Westinghouse) P/Ns 914F567-3 and -4, are maintained with an overhaul manual, while power relays, Sundstrand (Westinghouse) P/N 9008D09 series, are maintained with a component maintenance manual (CMM). This commenter states that the Common Support Data Dictionary (CSDD) defines overhaul as “The work necessary to return an item to the highest standard specified in the relevant manual.” Therefore, the commenter concludes that an “overhaul” should not be mandated for power relay, Sundstrand (Westinghouse) P/N 9008D09 series, because it is beyond the level of maintenance required to address the accumulation of contamination. Based on industry history, the commenter also states that maintenance (i.e., cleaning of the contacts and a check and repair) for power relay, Sundstrand (Westinghouse) P/N 9008D09 series, per the CMM, is sufficient.

The FAA agrees with the commenters that the use of the term “overhaul” in the first supplemental NPRM is not correct. Our intent was that the repetitive overhauls remove the metallic dust from electrical contact wear that accumulates in the power relays. We find that such removal can be accomplished by cleaning, inspecting, repairing, and testing of the generator power relays, auxiliary power relays, and external power relays (i.e., maintenance), per Boeing Alert Service Bulletin DC9-24A191, Revision 01, dated January 9, 2002 (described previously). Boeing Alert Service Bulletin DC9-24A191 references Westinghouse Overhaul Manual 24-20-46 (for relays, P/N 914F567-4) and Hamilton Sundstrand CMM 24-20-87 (for relays, P/N 9008D08 series) as additional sources of service information for accomplishing the proposed repetitive maintenance actions. However, as discussed previously, we have deleted the repetitive overhaul requirements for power relays, Sundstrand (Westinghouse) P/N 9008D09 series, from the second supplemental NPRM. Therefore, we have revised the second supplemental NPRM to require repetitive cleaning, inspecting, repairing, and testing of generator power relays, auxiliary power relays, and external power relays, Sundstrand (Westinghouse) P/N 914F567-4, only.

Request To Limit Actions to Cross-Tie Position

Two commenters request that the actions required by the first supplemental NPRM be limited to power relays in the cross-tie position only, which is identified as the unsafe condition in the first supplemental NPRM. One commenter states that there are no data to support the proposed actions for AC power relays at the generator power, auxiliary power, or external power positions. The commenters understand the FAA's concern that if all relays are the same P/N, there may be a risk of putting the wrong part in the cross-tie position. However, the commenters contend that operators have demonstrated their capability to deal with position-related restrictions for parts on airplanes, and that they can ensure that no relay, Sundstrand (Westinghouse) P/N 914F567-3, is installed in the cross-tie position.

One commenter states that it does not support the need for replacement of Westinghouse AC power relays, P/N 914F567-3, or the establishment of time between overhaul (TBO) limits for any of the AC power relays. The commenter uses relays, P/Ns 914F567-3, 914F567-4, 9008D09-1, and 9008D09-2, interchangeably in all seven positions, including the cross-tie position. The commenter states that its service experience indicates that each of these relays operate reliably well beyond the proposed TBO limits.

The FAA does not agree. Although there have been no reported cases of the power relays at the generator power, auxiliary power, or external power positions shorting out internally, the potential for an electrical short still exists when a power relay, Sundstrand (Westinghouse) P/N 914F567-3, is installed in those positions. The accumulation of conductive particle material on any power relays, Sundstrand (Westinghouse) P/N 914F567-3, can build an electrical path to its adjacent terminal and cause a phase-to-phase short circuit. Such a short circuit will result in internal arcing of the power relays and consequent smoke and/or fire in the cockpit and cabin. The second supplemental NPRM addresses that potential unsafe condition by removing generator power relays, auxiliary power relays, and external power relays, Sundstrand (Westinghouse) P/N 914F567-3, and periodically removing the build-up of conductive particle material from the generator power relays, auxiliary power relays, and external power relays, Sundstrand (Westinghouse) P/N 914F567-4.

However, we find that clarification of the wording of the unsafe condition of the second supplemental NPRM is necessary, because the identified unsafe condition for AC cross-tie relays, Sundstrand (Westinghouse) P/N 914F567-3 and -4, is now being addressed in AD 2001-20-15. Therefore, we have revised the unsafe condition specified throughout the second supplemental NPRM to read “to prevent internal arcing of the left and right generator power relays, auxiliary power relays, and external power relays, and consequent smoke and/or fire in the cockpit and cabin.”

Request To Include a New Paragraph for Spares

One commenter requests that a new paragraph be added to the first supplemental NPRM to state, “As of the effective date of this AD, no person shall install an AC power relay P/N 914F567-3 at the cross-tie relay position on any airplane.” The commenter states that this paragraph would prevent operators from putting an unmodified relay in the cross-tie position during the time period that unmodified relays will be available.

The FAA does not agree. As discussed previously, we have revised the second supplemental NPRM by removing the actions that would have been required for the AC cross-tie relays, Sundstrand (Westinghouse) P/N 914F567-3. Therefore, no change to the second supplemental NPRM is necessary in this regard.

Conclusion

Since these changes expand the scope of the originally proposed rule, the FAA has determined that it is necessary to reopen the comment period to provide Start Printed Page 44123additional opportunity for public comment.

Cost Impact

There are approximately 1,991 Model DC-9 airplanes and Model MD-88 airplanes of the affected design in the worldwide fleet. The FAA estimates that 1,219 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 2 work hours per airplane to accomplish the proposed inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $146,288, or $120 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

McDonnell Douglas: Docket 99-NM-90-AD.

Applicability: This AD applies to the following airplanes, certificated in any category, as listed in Boeing Alert Service Bulletin DC9-24A191, Revision 01, dated January 9, 2002:

McDonnell Douglas Model

DC-9-11, DC-9-12, DC-9-13, DC-9-14, DC-9-15, and DC-9-15F airplanes

DC-9-21 airplanes

DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-32F (C-9A, C-9B), DC-9-33F, DC-9-34, and DC-9-34F airplanes

DC-9-41 airplanes

DC-9-51 airplanes

DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) airplanes

MD-88 airplanes

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent internal arcing of the left and right generator power relays, auxiliary power relays, and external power relays, and consequent smoke and/or fire in the cockpit and cabin, accomplish the following:

Inspection

(a) Within 24 months after the effective date of this AD, perform a one-time inspection of the left and right generator power relays, auxiliary power relays, and external power relays, to determine if Sundstrand (Westinghouse) part number (P/N) 914F567-3 or -4, is installed, per Boeing Alert Service Bulletin DC9-24A191, Revision 01, dated January 9, 2002.

Replacement or Modification/Reidentification of Any Generator Power Relay, Auxiliary Power Relay, or External Power Relay, P/N 914F567-3

(b) If any generator power relay, auxiliary power relay, or external power relay, Sundstrand (Westinghouse) P/N 914F567-3, is found installed during the inspection required by paragraph (a) of this AD, within 24 months after the effective date of this AD, do either action(s) specified in paragraph (b)(1) or (b)(2) of this AD per the Accomplishment Instructions of Boeing Alert Service Bulletin DC9-24A191, Revision 01, dated January 9, 2002.

(1) Replace power relay having Sundstrand (Westinghouse) P/N 914F567-3 with either a serviceable power relay having Sundstrand (Westinghouse) P/N 9008D09 series or 914F567-4.

(2) Modify the power relay, Sundstrand (Westinghouse) P/N 914F567-3, to a -4 configuration.

Maintenance or Replacement of Any Generator Power Relay, Auxiliary Power Relay, or External Power Relay, P/N 914F567-4

(c) If any generator power relay, auxiliary power relay, or external power relay, Sundstrand (Westinghouse) P/N 914F567-4, is found installed during the inspection required by paragraph (a) of this AD, clean, inspect, repair, and test the relay, or replace the power relay with a serviceable power relay having Sundstrand (Westinghouse) P/N 9008D09 series or 914F567-4; per Boeing Alert Service Bulletin DC9-24A191, Revision 01, dated January 9, 2002; at the time specified in paragraph (c)(1) of this AD, except as provided by paragraph (c)(2) of this AD.

(1) Within 7,000 flight hours after installation of the generator power relay, auxiliary power relay, or external power relay, Sundstrand (Westinghouse) P/N 914F567-4, or within 24 months after the effective date of this AD, whichever occurs later.

(2) For airplanes on which the flight hours since installation of any generator power relay, auxiliary power relay, or external power relay, Sundstrand (Westinghouse) P/N 914F567-4, cannot be determined: Within 24 months after the effective date of this AD.

Repetitive Maintenance of Generator Power Relay, Auxiliary Power Relay, or External Power Relay, Sundstrand (Westinghouse) P/N 914F567-4

(d) Before or upon the accumulation of 7,000 flight hours on any generator power relay, auxiliary power relay, or external power relay, Sundstrand (Westinghouse) P/N 914F567-4 since accomplishing the action(s) required by either paragraph (b) or (c) of this AD, as applicable, clean, inspect, repair, and test; per Boeing Alert Service Bulletin DC9-24A191, Revision 01, dated January 9, 2002. Thereafter, repeat these actions at intervals not to exceed the accumulation of 7,000 flight hours on the power relay.

Alternative Methods of Compliance

(e) An alternative method of compliance or adjustment of the compliance time that Start Printed Page 44124provides an acceptable level of safety may be used if approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.

Special Flight Permits

(f) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Start Signature

Issued in Renton, Washington, on June 24, 2002.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 02-16407 Filed 6-28-02; 8:45 am]

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